If you use JEI (or /give) to give yourself a <hatchery:hatcheryegg> you get an egg with no NBT data. This egg works in all recipes that use eggs (such as cake, or the Pams Harvestcraft recipes) and can be converted to a vanilla egg.

If you breed two chickens, you get a <hatchery:hatcheryegg> with a lot of NBT data:
<hatchery:hatcheryegg>.withTag({eggColor: 14667419, display: {Name: "Chicken§r Egg"}, storedEntity: {IsChickenJockey: 0 as byte, HurtByTimestamp: 0, Leashed: 0 as byte, Health: 4.0 as float, Attributes: [{Base: 4.0, Name: "generic.maxHealth"}, {Base: 0.0, Name: "generic.knockbackResistance"}, {Base: 0.25, Name: "generic.movementSpeed"}, {Base: 0.0, Name: "generic.armor"}, {Base: 0.0, Name: "generic.armorToughness"}, {Base: 16.0, Name: "generic.followRange"}], FallFlying: 0 as byte, LeftHanded: 0 as byte, ForcedAge: 0, AbsorptionAmount: 0.0 as float, HandItems: [{}, {}], ArmorDropChances: [0.085 as float, 0.085 as float, 0.085 as float, 0.085 as float], EggLayTime: 8737, InLove: 0, DeathTime: 0 as short, ArmorItems: [{}, {}, {}, {}], CanPickUpLoot: 0 as byte, HandDropChances: [0.085 as float, 0.085 as float], PersistenceRequired: 0 as byte, id: "minecraft:chicken", HurtTime: 0 as short, Age: -24000}})

Observed Behavior: This egg cannot be crafted into a vanilla egg, and cannot be substituted for other ore dictionary eggs such as in the cooking recipes.

Expected behavior: This egg would be interchangeable with a vanilla egg, or at least convertible to one.

Closing this issue as a duplicate of #134